Right. My point is that whether the chocolate is D or DE is academic since for the consumer in the store it will always be only DE since any D will be batul.
It is hard to argue that the serial number is considered אפשר לברר.
It’s not completely academic. There can be a distinction in regards to a מינות issue for someone who wants to be machmir. IIRC Rav Moshe differentiates between bitul bshishim and bitul chad btrey in that regard.
Regarding the batch number, I can’t imagine it isn’t batul chad btrey in the first batch.
Also I wonder how does the crc label many items DE if this is a real issue? They require cleaning in between?